[Chromecast] Don't push buffers after the backend has been stopped

chromecast/media/cma/pipeline/av_pipeline_impl.cc

Index: chromecast/media/cma/pipeline/av_pipeline_impl.cc
diff --git a/chromecast/media/cma/pipeline/av_pipeline_impl.cc b/chromecast/media/cma/pipeline/av_pipeline_impl.cc
index 810cc6a45675550b9e0528f99c8661750f19e87f..808a56ba91a20484f12f5a942a58e506b64c8706 100644
--- a/chromecast/media/cma/pipeline/av_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/av_pipeline_impl.cc
@@ -277,6 +277,10 @@ void AvPipelineImpl::OnBufferDecrypted(
     LOG(WARNING) << "Can't decrypt with decrypt_context";
     buffer->set_decrypt_context(std::move(decrypt_context));
   }
+
+  if (!enable_feeding_)
+    return;
+
   pending_buffer_ = buffer;
   PushPendingBuffer();
 }